Linked from
The 16 pages that link to Musical scale, each with the reason it gives.
Vocal harmonyRelated: A shared scale supplies the pitch vocabulary for most arranged vocal parts.
Modal musicNarrower topic: Modes are particular ways of organizing pitches within scales.
Musical tuningNarrower topic: Tuning determines the pitch relationships within a scale.
Guitar soloNarrower topic: Scales supply note choices for many improvised guitar lines.
Musical noteRelated: Scales define which note pitches commonly belong to a musical passage.
XylophoneRelated: The bar arrangement maps a selected set of pitches into a playable sequence.